A so-called autonomous traveling type electric vacuum cleaner (i.e. referred to as a cleaning robot or an autonomous traveling type vacuum cleaner) for traveling on a floor surface while detecting an obstacle on the floor surface using a sensor and cleaning the floor surface by autonomously traveling the floor surface has been known. Other than the electric vacuum cleaner, autonomous traveling devices for performing, for example, indoor air clean, factory security and work such as transportation of luggage have been known. In this specification, these devices having autonomous traveling function are collectively referred to as a self-propelled electronic device.
Such a self-propelled electronic device is provided with various sensors for performing safety and secure self-propelled traveling.
For example, a self-propelled electronic device disclosed in Patent Document 1 includes, as traveling sensors for detecting an obstacle on a floor surface for self-propelled travelling, a front sensor and a ceiling sensor. The front sensor is provided for measuring a distance to an obstacle including a step, wall, column, furniture, and leg of a table or bed, etc. positioned at a lower forward of the self-propelled electronic device. The ceiling sensor is provided for detecting whether or not the self-propelled electronic device can pass below an obstacle at an upper forward of the self-propelled electronic device.
Further, Patent Document 1 discloses that the self-propelled electronic device includes a lifting switch for detecting lifting of a drive wheel from a floor surface, and a step sensor for detecting a level difference of the step on the floor surface positioned at the forward of the self-propelled electronic device. When the lifting switch detects the lifting of the drive wheel from the floor surface, it is detected by the output from the step sensor that the self-propelled electronic device is positioned near, namely, within a certain distance from the floor surface. In such a case, it is detected that a drive wheel is derailed by the level difference of the step on the floor surface. Then, the drive wheel is further driven to attempt an escape from the level difference of the step. When it is detected that the self-propelled electronic device is positioned far away from the certain distance from the floor surface, it is detected that the self-propelled electronic device is lifted up by a user, so that the drive wheel stops according to the disclosure of Patent Document 1.